Understanding Cerebral/Cortical Visual Impairment (CVI) and Hydrocephalus: How Vision Can Be Affected

Cerebral/Cortical Visual Impairment (CVI) is a neurological condition where the brain has difficulty processing visual information. Individuals with hydrocephalus are at an increased risk of developing CVI, particularly those who have experienced significant changes in brain pressure or complications from hydrocephalus. This article explores the relationship between CVI and hydrocephalus, the impact on vision, and how caregivers and healthcare professionals can support those affected.

What is Cerebral/Cortical Visual Impairment (CVI)?

CVI is the leading cause of childhood blindness and low vision. It occurs when there is damage or disruption to the visual pathways and processing centers in the brain, making it hard for the brain to interpret what the eyes are seeing. 

Individuals with CVI often struggle to make sense of what they see. This can impact everything from being aware of objects and maintaining visual attention to their surroundings, to visually recognizing items or people, navigating an environment, or knowing what is happening at a distance. A noisy or cluttered environment, feeling ill or tired, and/or fatigued can make using vision nearly impossible for someone with CVI. 

Unlike other types of vision impairment, the eyes themselves may function properly, but the brain struggles to process the visual signals. A person can even have perfectly healthy eyes and still have CVI. However, it is common for individuals with CVI to also have an ocular diagnosis. 

How is CVI Related to Hydrocephalus?

Hydrocephalus, a condition where excess cerebrospinal fluid (CSF) builds up in the brain, can create pressure that affects various parts of the brain, including those responsible for vision. Depending on the location and duration of the pressure, the pathways in the brain that control vision may be damaged or impaired.

Individuals with hydrocephalus, particularly those who have experienced prolonged pressure on the brain or have undergone multiple surgeries, may be at higher risk of developing CVI. In some cases, shunt malfunctions or blockages leading to increased intracranial pressure (ICP) may also contribute to the development of CVI. While early detection and treatment of hydrocephalus can help mitigate this risk, damage to the brain’s visual processing centers may still occur in some cases.

Signs of CVI in Individuals with Hydrocephalus

Each individual with CVI is impacted in a unique way. Some common manifestations of CVI include: 

• Inconsistent use of vision: Individuals may vary in their ability to look at items depending on the materials and/or environment. 
• Difficulty with visual recognition: Individuals with CVI may have difficulty recognizing objects, images, and people. They may have difficulty making eye contact, or only recognizing someone when they speak. They may rely on other strategies, such as touching the item to recognize it or relying on someone’s voice to know who is around them. 
• Impact of light: They may be drawn to light or only notice items with light and motion, or conversely find bright lights can be uncomfortable or overwhelming.
• Difficulty with depth perception and spatial awareness: This can lead to challenges navigating environments such as difficulty stepping off curbs, going down steps, or crossing thresholds. 
• Delayed visual responses: Individuals may take longer to look at or recognize items.
• Preference for viewing familiar objects: Familiar objects are often easier for individuals with CVI due to the repeated exposure of these objects.
• Difficulty with clutter and crowding: Clutter is a barrier to access for individuals with CVI. This includes both materials and environments. The more items that are presented the harder it can be for an individual with CVI to find and recognize the item they are looking for.

Diagnosis and Treatment of CVI

Diagnosing CVI requires a comprehensive evaluation by healthcare professionals, including ophthalmologists, neuro-ophthalmologists, optometrists, and neurologists. The diagnosis typically involves a combination of reviewing medical history, conducting a comprehensive eye examination, and performing a clinical functional vision assessment.

CVI is a lifelong condition, and an early diagnosis can help improve the quality of life for individuals with CVI. An individualized approach to accommodations and interventions, supported by a Teacher of Students with Visual Impairments (TVI), can make a meaningful difference. These approaches may include: 

• Compensatory Skills: Strategies and techniques that enable individuals with visual impairments the ability to access and better understand their world. These may include:
  • Context cues
  • Memory
  • Predictability
  • Auditory cues
  • Tactile cues/exploration
  • Smell
  • Color coding.
• Visual accommodations: Adjustments targeting the specific needs of the individual. Examples include: 
  • Reducing visual clutter
  • Using color as a visual support
  • Use high contrast, plain backgrounds for learning and presentations. Using target or task lighting to support the needs of the individual
• Environmental adaptations: Changes to the surroundings to make visual processing easier for individuals with CVI. These may include: 
  • Reduce visual clutter
  • Controlling environmental noise
  • Use spaces and positioning that limit movement around the individual with CVI to reduce distractions
  • Adjusting lighting to meet the individual’s needs
• Educational supports: Individualized accommodations for school-aged children, to ensure their academic success. These supports should be tailored to the unique needs of the individual with CVI and may include: 
  • Allowing and planning for visual breaks 
  •  Meaningful and systematic instruction
  • Accessible learning materials
  • Supportive seating

Supporting Individuals with Hydrocephalus and CVI

Caregivers and healthcare providers can play a crucial role in helping individuals with hydrocephalus and CVI learn to navigate their visual world. Here are a few ways to support those affected:

• Understand individual needs: Each person with CVI may experience vision challenges differently. Understanding the specific visual preferences and triggers of the individual can help caregivers create a supportive environment.
• Use a multisensory approach: Use a multisensory approach to incorporate different sensory channels into the learning process—auditory, tactile, visual, kinesthetic (movement), olfactory (smell), and taste.
• Consider high-contrast materials: For individuals with CVI, high-contrast objects and backgrounds are often easier to see. Using bright saturated colors against dark backgrounds may help improve visual attention and to support visual recognition.
• Modify learning and living environments: Reduce visual clutter and create more structured and predictable environments. Schools and homes can implement strategies like reducing visual clutter, creating a quiet space,  and ensuring consistent lighting to make navigation easier.
• Monitor vision changes: Since CVI is a neurological condition, any changes in hydrocephalus, such as increased intracranial pressure or shunt complications, may affect visual processing. Regular check-ups with healthcare professionals are essential to monitor any changes in vision or brain function.

Conclusion

Cerebral/Cortical Visual Impairment is one of the many challenges that can accompany hydrocephalus, particularly when increased pressure or brain surgeries impact the visual pathways. While CVI may impact how an individual processes visual information, early interventions, proper diagnosis, and environmental adaptations can support an individual to access their world. Caregivers, educators, and healthcare providers working together can help individuals with hydrocephalus and CVI achieve better outcomes by supporting them in engaging more fully with daily activities and experiences. Learn more about CVI and find support at CVINow.org.

Information you can trust! This article was produced by the Hydrocephalus Association in collaboration with Lacey Smith, M.Ed., TVI-CVI, and Hydrocephalus Parent. Copyright © 2024.